Gaze detection relates to the monitoring or tracking of eye movements to detect a person's gaze point. Various types of gaze detection systems and methods are known. For example products sold by Tobii Technology AB operate by directing near infrared illumination towards a user's eye and detecting reflection of the infrared illumination from the user's eye using an image sensor. Such a gaze detection system is described in U.S. Pat. No. 7,572,008. Other alternative gaze detection systems are also known, such as those disclosed in U.S. Pat. No. 6,873,314 and U.S. Pat. No. 5,471,542.
A gaze detection system can be employed as a user input mechanism for a computing device, using gaze detection to generate control commands. Eye control can be applied as a sole interaction technique or combined with other control commands input via keyboard, mouse, physical buttons and/or voice. It is now feasable to add gaze detection technology to many mobile computing devices, smart phones and tablet computers, and personal computers. Most standard-type web cameras and cameras integrated into mobile computing devices have a resolution of a few million pixels, which provides sufficient optical quality for eye-tracking purposes. Most mobile computing devices and personal computers also have sufficient processing power and memory resources for executing gaze detection software.